• Metro to take 7000 series out of service after defect was discovered in axle

  • Discussion related to DC area passenger rail services from Northern Virginia to Baltimore, MD. Includes Light Rail and Baltimore Subway.
Discussion related to DC area passenger rail services from Northern Virginia to Baltimore, MD. Includes Light Rail and Baltimore Subway.

Moderators: mtuandrew, therock, Robert Paniagua

  by STrRedWolf
 
YOLO wrote: Tue Oct 19, 2021 11:16 am so the rail guage on our system is 1429in and not the stand 1435in, could that be at play here?
You mean mm, not inches. 1435 mm, not 119 feet 7 inches... or "football stadium gauge". Nobody uses football stadium gauge for railroad operations (maybe operations of retractable roofs on football stadiums).
  by Sand Box John
 
ExCon90
I never heard the gauge is narrower than the standard 1435 mm. What was the reason for that?


The track gauge is narrower by 1/4" 6.35mm. The wheel sets are standard gauge. The reason is to reduce the lateral movement of truck (hunting) at speed on tangent track.
  by STrRedWolf
 
Sand Box John wrote: Wed Oct 20, 2021 9:52 am ExCon90
I never heard the gauge is narrower than the standard 1435 mm. What was the reason for that?


The track gauge is narrower by 1/4" 6.35mm. The wheel sets are standard gauge. The reason is to reduce the lateral movement of truck (hunting) at speed on tangent track.
I hear that the tighter gaugue is beyond the tolerances of standard gauge rail. Anyone know of the tolerances?
  by ExCon90
 
Sand Box John wrote: Wed Oct 20, 2021 9:52 am ExCon90
I never heard the gauge is narrower than the standard 1435 mm. What was the reason for that?


The track gauge is narrower by 1/4" 6.35mm. The wheel sets are standard gauge. The reason is to reduce the lateral movement of truck (hunting) at speed on tangent track.
Thanks for actually answering my question. Have other railways around the world had trouble with hunting on straight track by wheelsets that match the track gauge, or was WMATA's original decision based on speculation by someone who was new to the business? Or is it standard industry practice which somehow never gets mentioned?
  by Sand Box John
 
ExCon90
Thanks for actually answering my question. Have other railways around the world had trouble with hunting on straight track by wheelsets that match the track gauge, or was WMATA's original decision based on speculation by someone who was new to the business? Or is it standard industry practice which somehow never gets mentioned?


Hunting is an issue that has been know about for more then a hundred years. Lateral dampening in the truck suspension design has reduced it. Rolling stock center of gravity also has an effect on hunting. In the case of WMATA Metrorail reducing the track gauge reduces the lateral movement even more.

It should be noted that track gauge is nominal. It is increased in curves based on the sharpness of the curve and the amount of super elevation.
  by JDC
 
Metro is hosting a press conference now regarding the ongoing service reductions due to 7000-series not being used. The new press release says that the 7000-series will continue to be unavailable 'at least' through Oct. 31. To add more cars into service, Metro pulled some old 2000s and also 6000s that were undergoing repairs. https://www.wmata.com/about/news/Metror ... -10-25.cfm
  by farecard
 
Metro pulled some old 2000s and also 6000s that were undergoing repairs.
It sure looks like it is faster to fix the 6000's than to get new wheelsets for the 7000's. I'm surprised that WMATA has not given that aspect more publicity; that they haven't makes me think they are behind the curve on accomplishing the 6000 repairs.
  by Sand Box John
 
farecard
It sure looks like it is faster to fix the 6000's than to get new wheelsets for the 7000's. I'm surprised that WMATA has not given that aspect more publicity; that they haven't makes me think they are behind the curve on accomplishing the 6000 repairs.


WMATA's capacity to service its rolling stock is limited. Senses the completion of the 101 mile system they have added 8 bays to two existing shops and built one new 10 bay shop to shorten servicing turn around times and it still is not enough. They also lack enough qualified employees to preform all the various servicing and repair tasks. Toss in correcting servicing tasks that were done wrong in the first place and fixing a manufacturing defect you end up with the perfect a storm.
  by davinp
 
farecard wrote: Fri Oct 22, 2021 11:13 am
Metro pulled some old 2000s and also 6000s that were undergoing repairs.
It sure looks like it is faster to fix the 6000's than to get new wheelsets for the 7000's. I'm surprised that WMATA has not given that aspect more publicity; that they haven't makes me think they are behind the curve on accomplishing the 6000 repairs.
The 6000 series were pulled last year due to decoupling problems In late Sep 2021, Metro began to gradually bring them back in service after they were fixed. This means only a small amount of 6000 series cars are back in service. The 6000 series cars were mainly on the red line

Metro has less then 100 2000 series cars
  by farecard
 
Metro began to gradually bring them back in service after they were fixed. This means only a small amount of 6000 series cars are back in service
Exactly my point.
  • They are short of rolling stock.
  • They know how to fix the 6000's
  • They have many yet-unfixed ones
So delete the "gradually" from the above.
  by STrRedWolf
 
NPR picked up affiliate station WAMU's coverage, which has some tidbits.

Long story short:
  • Any fixes to the 7000 series have to be reviewed first by the Washinton Metrorail Safety Commission (WMSC), then done and inspected by WMSC).
  • The 2000 series was mothballed but now needs to be "rebooted" and inspected to get into service.
  • The 6000 series has the coupler defect that requires each repair to be inspected by the WMSC.
  • All buses and drivers are in service. All of 'em.
  • Metro's board is without a safety advisor or person w/safety experience, so they're hiring someone.
  by mmi16
 
Are the 7000's still running with their 'as delivered' axle/wheel sets? Or has WMATA maintenance been replacing them and are WMATA personnel doing the pressing of the wheels on the axles?